1. Use of present simple tense: The answer uses the present simple tense ("I believe," "it's important," "impressions count," "shows") to talk about general truths and opinions, which is appropriate for this kind of question.
2. Use of infinitive and gerund: The phrase "to be polite" uses the infinitive form to express purpose, and "showing politeness" uses the gerund as the subject of the clause, demonstrating a good range of grammatical structures.